Another Big One is coming: U.S. Geological Survey says an earthquake on the order of Loma Prieta, or greater, is likely to shake the Bay Area by 2032.

What many view as an inevitable disaster scenario -- toppled freeways, crumbled buildings, cracked pavement -- others see as an opportunity.

In this view, the San Andreas and Hayward faults are agents of urban renewal, their destructive force having a positive impact on the urban landscape. For starters, look what Loma Prieta did to open up San Francisco's waterfront.

"You're lucky you've got those earthquakes." That's what one San Francisco city planner says he hears when he goes to conferences around the country and tells fellow planners about the improvements made after the 1989 quake.

Nearly every major U.S. city has a legacy of neighborhood-gouging freeways from the 1950s and '60s, structures now universally recognized as monuments to bad planning.

In an earthquake-prone city like San Francisco, as Loma Prieta proved, they don't have to be permanent scars on the landscape.

When the next Big One hits, Robin Levitt is among those hoping a few more of the city's freeways crumble. Levitt is the architect and neighborhood activist who led a successful campaign in the late 1990s to replace the quake-damaged Central Freeway with an open, pedestrian-friendly boulevard just north of Market Street.

Today, Levitt proudly points out that what had been a "no man's land" under the old freeway has been transformed into the four-block-long Octavia Boulevard, what Levitt grandly describes as a "Parisian boulevard" treatment where cars share space with cyclists and pedestrians.

The cars are separated from the slower traffic by 5-foot-wide median strips landscaped with trees and plants -- another step in the "greening" of the city.

"In Europe, you don't have freeways running through cities, cutting up neighborhoods, the way they do here," Levitt notes. "In this country, we're finally learning that we can move people through cities without running freeways through them, that we can start to give the city back to the people who live here."

When the next earth-shaker hits, Levitt would like to see more of the Central Freeway go down, so that Octavia can be extended and Van Ness Avenue and Mission and Valencia streets can emerge from under the shadow of the existing overpass -- an idea that the Board of Supervisors itself has tentatively endorsed.

And let's be honest, don't some of the city's drearier edifices -- the institutional slab known as the Hall of Justice on Bryant Street, or the Federal Building on Golden Gate Avenue -- make you yearn for the next earthquake? If so, you can take heart from the fact that they both sit on soggy, unstable ground.

Author Grey Brechin ("Imperial San Francisco") is among those who think the next earthquake could improve the city's landscape. He points out that key parts of the city -- including the Civic Center, the Financial District, South of Market, and the Mission District -- sit on long-buried bay inlets, creeks, marshes and lakes.

Buildings sited over these underground bodies of water are sitting on unstable infill materials -- soggy, shaky foundations referred to as "liquefaction" zones by seismologists. They not only tend to form big sinkholes during an earthquake, but also amplify ground motion.

In the aftermath of the 1906 and 1989 earthquakes, you could identify the location of these subterranean water sources by noting the pattern of toppled and badly damaged buildings, especially South of Market. That region lost a lot of brick warehouses in 1989, many of which have since been replaced by live/work lofts.

The next time around, Brechin suggests, don't repeat this futile pattern of rebuilding on unstable ground. Instead, follow the path suggested by nature and open up the creeks and develop parkways along them.

This would have the added benefit of avoiding development in areas prone to flooding. And, as Brechin points out, any clearing of these generally low-lying flood zones will help prepare the city for the gradually rising ocean levels associated with global warming.

There is one major problem with this idea: The city's underground creeks are used as sewage trunk lines, so that any creek restoration program would require a major investment in new sewer lines. It's also unlikely that San Franciscans would support restoration of one creek in particular, Hayes Valley Creek, which flows under Civic Center.

As for other likely targets of urban renewal, what about that Lego on steroids, Sutro Tower? If that topples, Brechin suggests resurrecting sculptor Benny Bufano's idea of a monumental statue of St. Francis of Assisi on Mount Sutro. Or architect Bernard Maybeck's proposal for a copy of the Acropolis -- a symbol of wisdom and civilization replacing the structure that currently beams us "Desperate Housewives."

Although he'd hardly want to go on record favoring a San Francisco earthquake, at least one of Mayor Gavin Newsom's programs could get a big boost from the next Big One.

As part of his new $11 million "Better Streets" initiative, the mayor's aides have been pointing out that there is ' a lot of underutilized pavement in the city -- isolated, undeveloped dead-end streets, for example, or those extra-wide streets out in the Sunset District -- some 560 acres by current City Hall estimates.

The pocket parks and community gardens the mayor wants to create could, with a little pick-and-shovel work, replace some of the pavement that cracks in the next earthquake.

One Planning Department employee also mentioned the idea of redesigning earthquake-damaged streets to create "slow streets," or what the Dutch call "woonerfs."

These are resident-friendly streets that restrict traffic to narrow thoroughfares, while giving pedestrians wide sidewalks with natural landscaping and street furniture -- along the lines of Octavia's "Parisian boulevard" treatment. These more sophisticated street revamps don't come cheap however, costing on the order of $500,000 per block.

Then again, why wait for the next Big One? Boston didn't wait for a natural disaster to underground two miles of waterfront freeway and begin replacing its former route with a long swath of parks, public plazas, shops and housing. Seattle is considering a similar project along its waterfront.

San Francisco may well have to live with its ugly buildings, at least until the next big shaker, but the transformation of public spaces -- the liberation of neighborhood streets, the opening up of urban vistas, the tearing up and greening of superfluous pavement -- can begin immediately.

Thanks to the last major earthquake, there are positive examples of this kind of improvement on both sides of the bay. (Loma Prieta's shaking also helped heal the neighborhood around the damaged Cypress Freeway in Oakland.)

Not only would such projects help return the city to the people who live here, as Levitt advocates, but they could also make it safer in the next earthquake.

For one thing, there would be fewer elevated freeways to come tumbling down. And when was the last time anyone was buried in the rubble of a community garden?